How big can a user agent string get?

Question

If you were going to store a user agent in a database, how large would you accomdate for?

I found this technet article which recommends keeping UA under 200. It does

Answer 1

Since it's for database purposes and there is no practical limit i'd go for a UserAgents Table with UserAgentId as Int and UserAgentString as NVarChar(MAX) and use a foreign key on the original table.